von Willebrand Panel
Ordering Info & Methodology
Test Code
Cerner Synonyms
VWB
Von Willebrand Investigation, Von Willebrand Antigen, Ristocetin Co Factor, Von Willebrand Activity, vWF
Turn Around Time
Methodology
Immunoturbidimetric
Ordering Guide
Panel includes von Willebrand antigen and Ristocetin Co-Factor testing.
Specimen Requirements
Sample Type
Collection Container
Alternate Collection Containers
Citrated Plasma
Light Blue
1.5 mL
Add on stability
This is the length of time after sample collection that this analyte is stable. Test can be added to a previously collected sample if the time since collection is less than the add on stability time.
Minimum Volume
Add On Stability
Collection and Shipping Requirements
Freeze. Send frozen on dry ice. Must arrive at SPH frozen. Thawed specimens will be rejected.
Reference Intervals
Female Reference Interval
Age Category | Reference Interval | units |
---|---|---|
≥ 0 y | >0.50 | U |
Male Reference Interval
Age Category | Reference Interval | units |
---|---|---|
≥ 0 y | >0.50 | U |
Additional Notes
Measurement Uncertainty (MU)
Every laboratory value is an estimate of the true concentration of substance. MU is the 95% confidence interval around that estimate. 95% of the time, the true concentration will be within the range of the reported value ±MU. This value is based on analytical variability (precision) and does not reflect other factors such as sample collection and handling which may also affect the result.
Example
Reported sodium = 140 mmol/L
Sodium MU = 1%
Expanded uncertainty = 140 mmol/L ± 1% or 140mmol/L ± 1.4 mmol/L
Interpretation - the true value of sodium in the sample is in the range 138.6-141.4 mmol/L, with 95% confidence.
Measurement Uncertainty